Advertising sign



FIG. 1 is a front perspective view of an advertising sign, showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a left-side elevational view thereof;

FIG. 6 is a right-side elevational view thereof;

FIG. 7 is a front elevational view thereof; and,

FIG. 8 is a rear elevational view thereof.

The broken lines showing indicia on the front side of the design depict environmental matter and form no part of the claimed design. 

I claim the ornamental design for an advertising sign, as shown and described. 